Outcome of patients with acute coronary syndrome in hospitals of different sizes. A report from the AMIS Plus Registry.

To assess the impact of admission to different hospital types on early and 1-year outcomes in patients with acute coronary syndrome (ACS). Between 1997 and 2009, 31 010 ACS patients from 76 Swiss hospitals were enrolled in the AMIS Plus registry. Large tertiary institutions with continuous (24 hour/7 day) cardiac catheterisation facilities were classified as type A hospitals, and all others as type B. For 1-year outcomes, a subgroup of patients admitted after 2005 were studied. Eleven type A hospitals admitted 15987 (52%) patients and 65 type B hospitals 15023 (48%) patients. Patients admitted into B hospitals were older, more frequently female, diabetic, hypertensive, had more severe comorbidities and more frequent non-ST segment elevation (NSTE)-ACS/unstable angina (UA). STE-ACS patients admitted into B hospitals received more thrombolysis, but less percutaneous coronary intervention (PCI). Crude in-hospital mortality and major adverse cardiac events (MACE) were higher in patients from B hospitals. Crude 1-year mortality of 3747 ACS patients followed up was higher in patients admitted into B hospitals, but no differences were found for MACE. After adjustment for age, risk factors, type of ACS and comorbidities, hospital type was not an independent predictor of in-hospital mortality, in-hospital MACE, 1-year MACE or mortality. Admission indicated a crude outcome in favour of hospitalisation during duty-hours while 1-year outcome could not document a significant effect. ACS patients admitted to smaller regional Swiss hospitals were older, had more severe comorbidities, more NSTE-ACS and received less intensive treatment compared with the patients initially admitted to large tertiary institutions. However, hospital type was not an independent predictor of early and mid-term outcomes in these patients. Furthermore, our data suggest that Swiss hospitals have been functioning as an efficient network for the past 12 years.

Ku-deficient yeast strains exhibit alternative states of silencing competence.

In Saccharomyces cerevisiae, efficient silencer function requires telomere proximity, i.e. compartments of the nucleoplasm enriched in silencing factors. Accordingly, silencers located far from telomeres function inefficiently. We show here that cells lacking yKu balance between two mitotically stable states of silencing competence. In one, a partial delocalization of telomeres and silencing factors throughout the nucleoplasm correlates with enhanced silencing at a non-telomeric locus, while in the other, telomeres retain their focal pattern of distribution and there is no repression at the non-telomeric locus, as observed in wild-type cells. The two states also differ in their level of residual telomeric silencing. These findings indicate the existence of a yKu-independent pathway of telomere clustering and Sir localization. Interestingly, this pathway appears to be under epigenetic control.

A cell biological view of the siderophore pyochelin iron uptake pathway in Pseudomonas aeruginosa.

Pyochelin (PCH) is a siderophore produced and secreted by Pseudomonas aeruginosa for iron capture. Using (55) Fe uptake and binding assays, we showed that PCH-Fe uptake in P. aeruginosa involves, in addition to the highly studied outer membrane transporter FptA, the inner membrane permease FptX, which recognizes PCH-(55) Fe with an affinity of 0.6 ± 0.2 nM and transports the ferri-siderophore complex from the periplasm into the cytoplasm: fptX deletion inhibited (55) Fe accumulation in the bacterial cytoplasm. Chromosomal replacement was used to generate P. aeruginosa strains producing fluorescent fusions with FptX, PchR (an AraC regulator), PchA (the first enzyme involved in the PCH biosynthesis) and PchE (a non-ribosomic peptide-synthetase involved in a further step). Fluorescence imaging and cellular fractionation showed a uniform repartition of FptX in the inner membrane. PchA and PchE were found in the cytoplasm, associated to the inner membrane all over the bacteria and also concentrated at the bacterial poles. PchE clustering at the bacterial poles was dependent on PchA expression, but on the opposite PchA clustering and membrane association was PchE-independent. PchA and PchE cellular organization suggests the existence of a siderosome for PCH biosynthesis as previously proposed for pyoverdine biosynthesis (another siderophore produced by P. aeruginosa).

La place des instruments d'évaluation du risque de récidive dans la pratique de l'expertise psychiatrique pénale: l'exemple lausannois

Nous décrivons dans cet article la pratique de l'expertise psychiatrique pénale telle qu'elle est effectuée au centre d'expertises de l'Institut de psychiatrie légale du département de psychiatrie du CHUV à Lausanne. Y est notamment abordée la question de la place réservée à l'utilisation d'instruments d'évaluation du risque de récidive. Qu'ils soient actuariels ou à type de raisonnement clinique structuré, ces instruments nous paraissent pouvoir trouver à s'inscrire dans une démarche méthodologique rigoureuse, dans la mesure où celle-ci se déploie dans une perspective qui reste fondée sur la clinique.

Structural components in functional data

Analyzing functional data often leads to finding common factors, for which functional principal component analysis proves to be a useful tool to summarize and characterize the random variation in a function space. The representation in terms of eigenfunctions is optimal in the sense of L-2 approximation. However, the eigenfunctions are not always directed towards an interesting and interpretable direction in the context of functional data and thus could obscure the underlying structure. To overcome such difficulty, an alternative to functional principal component analysis is proposed that produces directed components which may be more informative and easier to interpret. These structural components are similar to principal components, but are adapted to situations in which the domain of the function may be decomposed into disjoint intervals such that there is effectively independence between intervals and positive correlation within intervals. The approach is demonstrated with synthetic examples as well as real data. Properties for special cases are also studied.

Long time behaviour of diffusing particles in constrained geometries; application to chromatin motion

Inspired by experiments that use single-particle tracking to measure the regions of confinement of selected chromosomal regions within cell nuclei, we have developed an analytical approach that takes into account various possible positions and shapes of the confinement regions. We show, in particular, that confinement of a particle into a subregion that is entirely enclosed within a spherical volume can lead to a higher limit of the mean radial square displacement value than the one associated with a particle that can explore the entire spherical volume. Finally, we apply the theory to analyse the motion of extrachromosomal chromatin rings within nuclei of living yeast.

Mutation of yeast Ku genes disrupts the subnuclear organization of telomeres.

The mammalian Ku70 and Ku86 proteins form a heterodimer that binds to the ends of double-stranded DNA in vitro and is required for repair of radiation-induced strand breaks and V(D)J recombination [1,2]. Deletion of the Saccharomyces cerevisiae genes HDF1 and HDF2--encoding yKu70p and yKu80p, respectively--enhances radiation sensitivity in a rad52 background [3,4]. In addition to repair defects, the length of the TG-rich repeat on yeast telomere ends shortens dramatically [5,6]. We have shown previously that in yeast interphase nuclei, telomeres are clustered in a limited number of foci near the nuclear periphery [7], but the elements that mediate this localization remained unknown. We report here that deletion of the genes encoding yKu70p or its partner yKu80p altered the positioning of telomeric DNA in the yeast nucleus. These are the first mutants shown to affect the subnuclear localization of telomeres. Strains deficient for either yKu70p or yKu80p lost telomeric silencing, although they maintained repression at the silent mating-type loci. In addition, the telomere-associated silencing factors Sir3p and Sir4p and the TG-repeat-binding protein Rap1p lost their punctate pattern of staining and became dispersed throughout the nucleoplasm. Our results implicate the yeast Ku proteins directly in aspects of telomere organization, which in turn affects the repression of telomere-proximal genes.